You weren't supposed to, that fight is very similar to the Revan VS Malak fight on the Leviathan.
Mild spoiler for the Demo:
Much of the Demo's plot is considered 'old lore' now, after Corellia the player will get to experience two new planets before your Master's sacrifice (One of these planets is Nar Shaddaa which will appear in Act 1 and the other planet, alongside your Master's sacrifice, will appear in Act 2).
Your player's Jedi Master is named "Quan Drayen".
For the events of ROR to align with the events of SWTOR, the player would have to pick very specific dialogue choices and actions. This is because we can't, and shouldn't, sacrifice playability just to compromise with TOR. The ROR mod is planned to be divided into two playable versions, the Canon version and the non-Canon version.
The Canon version will have the events of the Revan novel play out which will mean T3-M4 is dead, the Exile is betrayed by Lord Scourge and Revan was imprisoned by Vitiate for the next 100 years.
The Non-Canon version will NOT follow the events of the Revan novel, some things might still exist like Dromuund Kaas, Nathema, Scourge and Vitiate but that's about it. Revan would've most likely have been freed by the Jedi Exile and would be able to interact with your player character.
Also, the player can still customize their Revan and Exile to their heart's content despite what version they play. You can set it so that a male Light Side Exile get killed by Scourge and a female Dark Side Revan is imprisoned for 300 years in the Canon Version OR you can meet the canon male Light Side Revan in the Non-Canon version.
Of course, if Revan is female that would mean that Revan's canonical son, Vaner Shan, isn't born and if he isn't born that means Satele Shan isn't born either. In my opinion, don't worry about what is or isn't canon to TOR, just try to have fun playing the mod the same way you'd have fun playing Kotor 2 even if Exile is supposed to be light side female named "Meetra Surik". Once the mod is fully finished, I'm sure we'll open a thread about the precise Canon path for TOR and what Logan considers to be the Canon ending for ROR out of all the possible endings.
I believe the Non-Canon version will be developed before the Canon one, so players would experience the cooler Non-Canon playthrough first!
The Non-Canon version of Revan you'd meet would probably be neutral, as you said he is either the Dark Lord of the Sith or the parodical knight who saved the Republic. The reason Revan becomes neutral is because he regained his full identity through recovering all of his lost memories, Revan no longer wishes to be the Dark Lord of the Sith as he knows that Vitiate is using Revan as a pawn, he doesn't want to be a Jedi hero either as that identity was programmed into him by the Jedi Council and he alone knows that a greater threat lurks in the Unknown Regions.
The Revan you'd meet would be neutral and would, for the most part, be the same regardless of if he/she was Light Side or Dark Side... but the consequences of the LS and DS endings would still remain (Namely Carth hating Revan for betraying the party and Bastila believing Revan to still be a Sith Lord if Dark Side).
Bear this in mind, everything I just said about Revan's alignment is based souly on what I think is easiest both lore wise and programming (as in actual modding implementation) wise. Logan, the lead mod author, could easily swoop in and make Revan totally different when the time comes to add him to the mod. So take everything I've said with a grain of salt.
Not necessarily, Revan's "Revenge" could be targeted against the True Sith. Of course, since the player has the option of being either Light Side or Dark Side as well as being aligned to various different groups and factions it could be entirely possible that the player could stand in the way of Revan's ambitions making Revan a sort of antagonist.
The ROR mod was first drafted in 2008, due to the numerous rewrites since then the "Revenge of Revan" title might not make too much sense if you're wishing to follow a TOR friendly Canon playthrough of ROR.